Merge two word documents into one document

Is there a way to combine two versions of the same Word for Mac 2011 into one document?

I have multiple revisions with comments from co-authors and would like to combine the documents with comments into one document.

Note: I am not interested in the insert file method that is used to insert a document into another document, essentially combing two documents into 1. I want to "merge" two versions into 1 version.